title: Loss-of-function of OsSTN8 suppresses the photosystem II core protein phosphorylation and interferes with the photosystem II repair mechanism in rice (Oryza sativa).
abstract: STN8 kinase is involved in photosystem II (PSII) core protein phosphorylation (PCPP). To examine the role of PCPP in PSII repair during high light (HL) illumination, we characterized a T-DNA insertional knockout mutant of the rice (Oryza sativa) STN8 gene. In this osstn8 mutant, PCPP was significantly suppressed, and the grana were thin and elongated. Upon HL illumination, PSII was strongly inactivated in the mutants, but the D1 protein was degraded more slowly than in wild-type, and mobilization of the PSII supercomplexes from the grana to the stromal lamellae for repair was also suppressed. In addition, higher accumulation of reactive oxygen species and preferential oxidation of PSII reaction center core proteins in thylakoid membranes were observed in the mutants during HL illumination. Taken together, our current data show that the absence of STN8 is sufficient to abolish PCPP in osstn8 mutants and to produce all of the phenotypes observed in the double mutant of Arabidopsis, indicating the essential role of STN8-mediated PCPP in PSII repair.
authors.affiliation: Department of Molecular Biology, Pusan National University, Busan, 609-735, Korea; Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, 711-873, Korea.
authors.forename: Krishna
authors.initials: K
authors.lastname: Nath
authors.forename: Roshan Sharma
authors.initials: RS
authors.lastname: Poudyal
authors.forename: Joon-Seob
authors.initials: JS
authors.lastname: Eom
authors.forename: Yu Shin
authors.initials: YS
authors.lastname: Park
authors.forename: Ismayil S
authors.initials: IS
authors.lastname: Zulfugarov
authors.forename: Sujata R
authors.initials: SR
authors.lastname: Mishra
authors.forename: Altanzaya
authors.initials: A
authors.lastname: Tovuu
authors.forename: Nayeoon
authors.initials: N
authors.lastname: Ryoo
authors.forename: Ho-Sung
authors.initials: HS
authors.lastname: Yoon
authors.forename: Hong Gil
authors.initials: HG
authors.lastname: Nam
authors.forename: Gynheung
authors.initials: G
authors.lastname: An
authors.forename: Jong-Seong
authors.initials: JS
authors.lastname: Jeon
authors.forename: Choon-Hwan
authors.initials: CH
authors.lastname: Lee
mesh_terms: D055785:Gene Knockdown Techniques; D008027:Light; D016254:Mutagenesis, Insertional; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D010641:Phenotype; D010766:Phosphorylation / Q000235:genetics; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D011494:Protein Kinases / Q000172:deficiency* / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency* / Q000235:genetics* / Q000378:metabolism; D020524:Thylakoids / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; C504925:STN8 protein, Arabidopsis
keywords: D1 protein degradation; STN8 kinase; high light illumination; photosystem II core protein phosphorylation; photosystem II repair; rice